Photophysical and Photocatalytic Properties of Zn^sub 3^M^sub 2^O^sub 8^ (M = Nb, Ta)

• Published in: Journal of the American Ceramic Society Vol. 95; no. 1; p. 227
• Main Authors: Noh, Tae Hoon, Cho, In-Sun, Lee, Sangwook, Kim, Dong Wook, Park, Sangbaek, Seo, Se Won, Lee, Chan Woo, Hong, Kug Sun
• Format: Journal Article
• Language: English
• Published: Columbus Wiley Subscription Services, Inc 01.01.2012
• Subjects: Aqueous solutions; Ceramics; Crystal structure; Diffraction; Photocatalysis
• ISSN: 0002-7820; 1551-2916

The ... (M = Nb, Ta) compounds with layered crystal structures were prepared by a conventional solid-state reaction method, and their electronic-band structures, optical properties, and photocatalytic activities were investigated. The prepared compounds were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis diffuse reflectance, and Mott-Schottky measurement. The UV-Vis diffuse reflectance spectra revealed ... and ... exhibited band gaps of 4.1 and 4.5 eV, respectively. From the electronic-band-structure calculations using DFT method, it was found that the valence band in both compounds was constructed by the hybridization of Zn 3d and O 2p orbitals, whereas the conduction band was consisted of Nb 4d (...) and Ta 5d (...) orbitals. The photocatalytic activity of both compounds was examined by the measurement of the ... production rate in an aqueous methanol solution under UV light irradiation. The ... with a larger band gap exhibited higher activity than ..., which was attributed to its higher reduction potential resulting from the difference of its electronic-band configuration. (ProQuest: ... denotes formulae/symbols omitted.)